Duhhhhh, must have been written by a Walking Dead fan.
I can buy a couple dozen high wattage green lasers from China dirt cheap, each in itself many times stronger than your average pointer, strip them down to the bare emitter and using a machined aluminum plate can align these lasrs so they are virtually parallel over a long distance.
Then I would mount it on a quick traverse gimbal with a high power zoom camera. It would be portable, able to literally pop out of the roof of an obscure beater.
When I was just 14 I salvaged an old movie projector lamp, bought a huge magnifying glass, made a tube and found the best focus point, mounted it on a piece of wood like a rifle stock.
This was back in the 70’s.
Yes, those green lasers are amazingly bright.